Abstract:
A large foF2 data base was collected for the four magnetic storms occurring in January
10, 1976; April 12-13, 1981; October 29, 1973 and July 8, 1975; for the low latitude station
of Manila (14.70
N) in the East Asian sector. Also, plots of D(foF2) deviations versus time
(UT) and that of the interplanetary magnetic field component (Bz) versus time (UT) for the
low latitude station were analyzed.
From our analysis, it was observed that there is a direct variation between Bz and the
F2 region response. Davis et al (1997) have shown that a southward turning with change in
Bz of δBz > 11.5nT results in foF2 showing a marked decrease in amplitude reaching a
minimum value of 20hrs after the southward turning. It was also observed that there is
homogeneity in the response of F2 region at low latitude stations (i.e. foF2 enhancement)
irrespective of the period of storm event, but more pronounce during intense storms which
was in agreement with Adeniyi, 1986; Mikhailov et al, 1994; who states that the positive
phase in most cases (90%) is observed at equatorial latitudes during magnetic
disturbances.